A voice command device (VCD) is a device controlled with human voice. By dispensing with buttons, dials and switches, consumers can easily operate appliances with their hands full or while doing other tasks. For example, consumers can operate their television or mobile phones with voice-activated commands. VCDs can be speaker-independent, responding to multiple voices, regardless of accent or dialectal influences. VCDs can be found in various applications, including computer operating systems, commercial software for computers, mobile phones, cars, call centers, and internet search engines.